Legal
Privacy Policy
What Inku collects, what it does not, and how to erase it. Short, plain, and current.
Inku is a Japanese learning app for iPhone and the web. This policy explains what information we collect, how we use it, and the choices you have. We try to keep it short and plain.
If something here is unclear, email us at app@inkujapanese.com and we will explain.
The short version
- Your learning is stored locally on your device or browser.
- We do not run our own servers that store your progress.
- We do not sell your data.
- We do not run ads.
- Web Pro and iPhone Pro are separate purchases on separate catalogs. A web subscription does not unlock or redeem in the iPhone app, and an iPhone subscription does not unlock the web app.
- Optional product analytics are off until you choose to enable them.
- You can clear local learning data from the app or browser. Deleting an app does not necessarily delete copies you exported or backed up.
Information stored on your device
Inku saves your learning data locally using the storage provided by your phone or browser. This includes:
- Which characters, words, and phrases you have reviewed.
- How you answered each review (remembered or did not remember).
- Your streak, daily ink drops, and overall progress.
- Your onboarding answers (level, goals, pace) and the plan we built from them.
- Any cards or phrases you flag as broken.
Your learning data does not leave your device unless you choose to export, share, restore, or otherwise send it. Inku supports manual backup files; anyone with a backup file may be able to read or import its contents, so keep it private.
Android system backup and device transfer are disabled for Inku. On Apple devices, the operating system may include app data in a device or iCloud backup according to your settings and Apple's policies.
Information we receive
Subscription status
If you subscribe to Inku Pro, we receive purchase and entitlement information needed to unlock Pro features on the store where you bought them. We do not receive your full payment-card details. On iPhone, Apple handles In-App Purchase. On the web, RevenueCat Web Billing handles checkout. RevenueCat also helps us manage subscription status on both stores. Web Pro and iPhone Pro are not interchangeable, and there is no account or progress sync in v1.
RevenueCat records a customer country from the store transaction or, when that is unavailable, from the country associated with the customer's last-seen IP address. RevenueCat says it drops the raw IP address after determining the country.
Optional product analytics
If you opt in, PostHog receives limited app-interaction events, app version information, and a random installation identifier. We use this to understand which parts of Inku are useful and where people get stuck. We do not send your learning answers, notes, email address, or advertising identifiers. You can turn analytics off in Settings.
Crash and diagnostic information
Sentry receives crash reports and technical diagnostics so we can find and fix problems. This reporting is enabled by default and can be turned off in Settings. Reports may include:
- Device model and operating-system version.
- App version.
- Scrubbed error type, operation category, stack and debug information, release identifiers, and related technical context.
We do not set a Sentry user identity or attach your learning content to these reports.
Feedback emails
If you use the in-app “Flag” feature or email app@inkujapanese.com, we see whatever you type, plus the email address you send from.
We do not request GPS or precise location, contacts, photos, microphone audio, browsing history, or content outside Inku. Services reached over the internet necessarily receive network information such as an IP address, which can sometimes imply an approximate area.
Website analytics
This website uses Google Analytics 4 to measure page visits and actions such as App Store and study-in-browser link clicks. We do not send email addresses or other direct identifiers in analytics events. The analytics script does not load when your browser sends a Do Not Track signal.
Optional email tips
The free kana chart page includes an optional email form. The chart is available without signing up. The form reports success only after a configured provider confirms that your address was stored. We record the email address, the page and form placement, campaign attribution, the consent time and version, delivery state, and a deduplication key.
No email provider is enabled by default. Before enabling one, we will name the processor and retention period here. You can unsubscribe from any tip email or ask us to delete your address at app@inkujapanese.com.
How we use this information
We use the information we collect to:
- Measure whether a change to the app is helping people learn.
- Diagnose and fix bugs.
- Keep your Inku Pro subscription in the right state.
- Respond when you email us.
- Measure which website pages lead to App Store or browser-app interest.
- Send optional Japanese tips when you explicitly subscribe.
We do not use your data to train AI models. We do not build a behavioral profile of you. We do not share your data with advertisers.
Third-party services
Inku uses a small number of third-party services. Here is what each one sees:
Apple App Store
If you install Inku from the App Store, Apple receives information about the download. If you buy iPhone Pro, Apple processes the In-App Purchase and receives the billing information.
RevenueCat (subscription management and Web Billing)
RevenueCat receives a signal when you subscribe, renew, or cancel so Inku can unlock Pro features on that store. RevenueCat does not receive your full card information from Apple In-App Purchase. It receives an app-generated customer identifier, purchase information from the applicable store, and a customer country determined as described above.
Web Pro is sold through RevenueCat Web Billing, not through Apple In-App Purchase and not through a homemade checkout on this marketing site. RevenueCat Web Billing processes the web payment and records the web entitlement on a web-only product catalog. That web entitlement does not unlock the iPhone app, cannot be redeemed in the iPhone app, and an Apple purchase does not unlock or redeem in the web app.
PostHog (optional product analytics)
PostHog receives the limited app-interaction data described above only when you opt in. You can withdraw that choice in Settings.
Sentry (crash and error reporting)
Sentry receives crash reports and technical error information. These are used to maintain app reliability. You can opt out in Settings.
ElevenLabs (voice audio)
We use ElevenLabs to pre-record Japanese pronunciation files before release. The iOS and web apps do not generate speech on demand or send your learning activity to ElevenLabs. Approved audio may be included with the app or delivered from a separately disclosed content host.
Google Analytics (website measurement)
Google Analytics receives limited website visit and action data when Do Not Track is not enabled. We use it to understand which pages help people find Inku and which App Store or study-in-browser links are used. We do not send email addresses in analytics events.
Website and web-app hosting
The Inku marketing website is hosted by Cloudflare Workers. The web learner is hosted by Expo's EAS Hosting, which also uses Cloudflare Workers. These hosting and content-delivery services may receive an IP address, browser or user-agent information, request time, requested path, region, duration, and security-log information needed to deliver, monitor, and protect the service. For web-app server requests, EAS Hosting derives continent, country, region, city, approximate latitude and longitude, and timezone information before forwarding the request to Inku's server route. Inku does not read those geographic headers. The providers retain information under their configured service settings and published policies.
AI providers (future features)
If we ship an AI-powered feature later (for example, a conversational practice partner or speech feedback), we may send the text or audio you produce to a third-party AI service. We will only send what is needed for the feature to work, and we will update this policy before the feature ships so you know exactly what is involved.
Where your data is stored
Your learning data is stored locally on your phone or in your browser. Copies may also exist in manual backups you create or in an operating-system backup under the platform provider's control.
Crash and diagnostic reports flow to Sentry. Optional app-interaction events flow to PostHog only after you opt in. Subscription information flows to RevenueCat and, for iPhone purchases, Apple. Website measurement can flow to Google Analytics when Do Not Track is not enabled.
These providers may process information in countries other than the one where you live. Their privacy policies describe their locations, safeguards, and retention practices.
How long we keep your data
- Local learning data: until you clear it, remove the app or browser data, or replace it by importing a backup. Exported backups remain wherever you saved or shared them.
- Subscription records: Apple, RevenueCat, and RevenueCat Web Billing retain their own records according to their policies, contracts, legal obligations, and configured settings.
- Analytics and diagnostics: retained according to the settings and policies of PostHog and Sentry.
- Optional email tips: no provider is enabled by default. We will publish the processor and retention period before enabling capture.
How to delete your data
Use Inku's data controls where available, or clear the app or browser's local storage. Removing the app normally removes its local data, subject to operating-system backups and any manual backup files you created.
Analytics can be disabled and diagnostic reporting can be opted out in Settings. Because we do not attach your account identity to these records, we may not be able to locate a particular anonymous event. You can still email app@inkujapanese.com and we will help with any information we can reasonably identify.
If you subscribed to email tips, use the unsubscribe link in any email or contact app@inkujapanese.com to ask us to delete the address.
You can stop paying for Inku Pro at any time by managing your subscription through the store where you purchased it: Apple for iPhone, or RevenueCat Web Billing for web (see our Terms of Service for details).
Security
Every network request the app makes is sent over HTTPS. Diagnostic data and subscription signals are encrypted in transit.
No system is perfect. If we discover a security incident that affects information we hold, we will investigate and provide any notice required by applicable law.
Children's privacy
Inku is not directed at children under 13. We do not knowingly collect information from children under 13. If you believe a child is using the app, email app@inkujapanese.com and we will help.
Users between 13 and the age of majority in their country should have a parent or guardian review this policy first.
Your rights
Depending on where you live, you may have the right to:
- Access the data we hold about you.
- Correct it.
- Delete it.
- Object to certain processing.
Because most of your data lives on your device, you already have full access to it. For the anonymous diagnostic data we hold through our providers, email app@inkujapanese.com and we will help.
Changes to this policy
If we change this policy in a way that affects you, we will update the date at the top and provide an appropriate notice in the app, on this website, or through the relevant app store. Small editorial edits (typos, clearer phrasing) do not trigger a notice.
Contact us
Questions about this policy or your data:
Inku is operated by Bao Hua, a sole proprietor based at The Ampersand, 140 10 Avenue SW, Calgary, AB T2R 0A3, Canada.